Seeing the High Energy Sky

Science fiction novels often try to help us understand what it might be like to see through the eyes of a being much different from ourselves. For example, our eyes only perceive a limited portion of the energy that bathes our planet all the time.

Take a look at this visualization of the Galactic Center through the eyes of the European Space Agency's Integral orbiting observatory, the most sensitive gamma-ray observatory ever launched. Today, it celebrates ten years of observations.

(Visualize the Galactic Center with ESA's Integral video)

The central region of our Milky Way, the Galactic Bulge, is a rich host of variable high-energy X-ray and gamma-ray sources. Thanks to regular observations by Integral over the last ten years, this dynamic environment has been charted in extensive detail, as revealed in this special anniversary video.

A number of these sources, which include X-ray binary systems with a black hole or a neutron star, pulsars and remnants of supernova explosions, only shine brightly for a limited period of time. In some cases, they appear as a sudden bright flash and disappear shortly afterwards, whereas others are more persistent.

The effect of this constantly changing environment gives the Galactic Bulge the appearance of a dramatic cosmic light show.

Inhabitants of Kardashev Type III civilizations can harness the full power of their entire galaxy; why shouldn't you be more aware of the exotic structures that surround us in our own galactic neighborhood? Sure, we Earthlings are only at about Kardashev 0.7, but we can dream, can't we?

(Integral science highlights)

One nearby black-hole binary, Cygnus X-1, is currently in the process of ripping a companion star to pieces and gorging on its gas.

Studying this extremely hot matter just a millisecond before it plunges into the jaws of the black hole, Integral has found that some of it might be making a high-speed getaway thanks to structured magnetic field lines acting as an escape tunnel.

High-speed escapes have also been seen at the Crab Nebula, the remains of a supernova explosion seen from Earth in 1054, and which hosts a pulsar at its heart.

Until Integral began studying these rapidly spinning neutron stars it was uncertain exactly how they accelerate particles to enormous energies exceeding those from even the most powerful man-made particle accelerators on Earth, like CERN’s Large Hadron Collider.

By studying the polarisation – alignment – of the waves of high-energy radiation originating from the Crab Nebula, Integral found that the radiation is strongly aligned with the rotation axis of the pulsar.

This implies that a significant fraction of the particles generating the intense radiation must originate from an extremely organised structure very close to the pulsar, perhaps even directly from the powerful jets beaming out from the spinning stellar core.